1. Field of the Invention
The present invention relates to an apparatus and method for use in video frame imaging; more specifically, the present invention is directed to a printer and related system and method having video image capture capabilities and allowing controlled video frame and print image data transfer between the printer and a personal computer ("PC") through a data port.
2. Description of Related Art
A conventional video frame imaging system includes a video capture device ("VCD") for capturing single frame video images from any device capable of producing and making available for capture composite video data. Composite video data for capture by a VCD is obtainable from various devices, including, for example, digital cameras, televisions ("TVs"), video cassette recorders ("VCRs"), and video camera/recorders ("camcorders"). A VCD typically is implemented in a frame imaging system using one of two basic strategies, and typically the VCD, regardless of implementation strategy, comprises certain basic operational components.
In one conventional implementation the VCD takes the form of a printed circuit card assembly that is installed by plug-in connection as an optional enhancement for a PC. In such a case, the VCD is plugged in under the housing of the PC's control unit or main hardware box and CPU, and is thereby connected to the PC bus to enable electronic interface with the PC.
Such a VCD implementation presents the user with several challenges. Installation of the VCD requires the user to remove the housing of the control unit and access the installation site. The user must select the appropriate place for VCD installation, and also must reconfigure the PC to accommodate the newly installed VCD. These tasks may be particularly daunting for the "average" PC user.
Alternatively, conventional implementation of a VCD in a frame imaging system may involve use of an external VCD unit that is connected to a PC through a parallel port, which usually is located in the rear of the PC and conventionally reserved for enabling a printer connection to the PC. Accordingly, this VCD implementation presents a problem when use is sought of both the external VCD and a printer. Since printer usage requires connection of the printer through the parallel port, the user is forced to choose between arranging the PC for use with the VCD or with the printer (i.e., with only one of these "peripheral devices"). And the user must connect and disconnect the peripheral devices every time a new selection of a peripheral device is made.
The conventional solution to the choice-of-peripheral device problem involves the installation of a multi-line peripheral device switch interposed between the peripherals and the PC. A switch of this type enables ready selection of and (re)connection of the desired peripheral to the PC. However, use of such a switch itself introduces problems. Such switches may be of low quality, and may in certain instances introduce undesirable noise in the signals conducted therethrough, causing intermittent and untimely function problems for the printer, or for the VCD. Moreover, the use of even a theoretically perfect multi-line peripheral device switch involves additional operating complexity and expense of the kind the typical PC user wishes to avoid, and generally comprises a solution lacking in operational elegance.
Referring to FIG. 1 (prior art), a typical video frame imaging system 12 is shown with an externally operating VCD 10. Video frame imaging system 12 also includes a computer 14, a printer 16, and a multi-line peripheral device switch 18.
VCD 10 includes analog-to-digital ("A/D") converter 22, video capture control circuit 24, video field frame memory 26, and parallel port connector (or "parallel port") 28. Composite video data, being transferred over a line 20 from, for example, a camcorder (not shown), is received by VCD 10 via a standard "RCA" connector or "jack" (i.e., a pin and shell type connector) and inputted to analog to digital ("A/D") converter 22. The received composite video data may, for example, be in standard NTSC (National Television Systems Committee) format or PAL (Phase Alternating Line) format. The received composite video data is sampled and digitized by A/D converter 22. The composite video data includes luminance and chrominance information used in generating a frame image. The output of A/D converter 22 is coupled to the input of video capture control circuit 24. Video capture control circuit 24 operates to, among other things, access the digitized composite video data from A/D converter 22 and transfer it to video field frame memory 26 to which video capture control circuit 24 is in operative electrical connection. Video capture control circuit 24 also is operatively connected to parallel port connector (or "parallel port") 28 through which connection is made by VCD 10 to switch 18.
Switch 18 makes possible operative electrical connection between either VCD 10 and computer 14, or printer 16 and computer 14. For example, in FIG. 1, switch 18 is connected to parallel port connector (or "parallel port") 28 of VCD 10 and to parallel port connector (or "parallel port") 32 of computer 14. Thus, digitized composite video data may be transferred by switch 18 from VCD 10 to computer 14 through parallel port connecter 32 of computer 14. The printer is not electrically connected to the computer 14 in this example. To connect the printer, one would move the switch from position "A" to position "B".
Computer 14, which may be a PC, includes in memory (not shown) port I/O driver software 34, video capture software 36, other graphics application software 38 and printer driver software 40. I/O driver software 34 allows computer 14 to operatively interface with connector 32 to handle data transfer to and from port 32. Software 34 also can be used by computer 14 to handle receipt of digitized video data, and to prepare the digitized video data for storage and processing by computer 14. The prepared digitized video data then can be processed, as is known to those skilled in the art, by conventional video capture software 36. Computer 14 uses software 36 to convert the digitized video data for display on a video monitor (not shown) of computer 14 using a standard format such as, for example, a "640.times.480 pel VGA" format. Typically, software 36 also allows the user to adjust parameters such as brightness, hue, sharpness, etc., and implements the saving of files of the resultant video data in typical 24-bit RGB color graphic file formats (e.g., TIFF (Tagged Image File Format), BMP (Bit Map), and JPEG (Joint Photographic Exports Group)). These files can then be used by graphic application software 38 that is loaded on computer 14 and interfaces with the other resident software. Driver software 34 and capture software 36 are able to interface for data transfer and for operation.
Graphics application software 38 uses the video files to manipulate print files that are used to generate printed images of the video images contained in the files using printer driver software 40. Alternatively, video data files may be communicated directly (without further manipulation/enhancement) from video capture software 36 to printer driver software 40 for the purpose of creating print images.
Printer driver software 40 generates the print image signals or data used in directing printer 16 to produce images corresponding to the desired video images. However, in this conventional system, transferring print signals to printer 16 and printing the images using printer 16 is not possible until switch 18, which necessarily would have been set to permit transfer of the video frame data from VCD 10 to computer 14, has been manually (re)adjusted to allow transfer of print image data between computer 14 and printer 16.
The present invention not only totally avoids the problems associated with manually installing a VCD card into a PC or other computer (when that approach is selected), the present invention also completely avoids the operational inadequacies associated with using a computer, a separate VCD, and a separate printer in conjunction with one another.